Pen



1.1: a perspective view of my new design;

1.2: a rear perspective view of my new design;

1.3: a left side elevational view thereof;

1.4: a right side elevational view thereof;

1.5: a front elevational view thereof;

1.6: a back elevational view thereof;

1.7: a top view thereof; and

1.8: a bottom view thereof. 

CLAIM The ornamental design for a pen, as shown and described. 